Why You Weigh Less at the Equator

You probably know that gravity is less on the moon than on Earth. Weight is a measure of the force of gravity pulling on an object, so you’d weigh less on the moon than on Earth. But gravity is the same all over Earth, right?

The Back Story

Actually, Earth’s gravity is not as uniform as you might think. Several factors cause gravity to vary around the globe.

Credit: NASA

Source: http://en.wikipedia.org/wiki/File:GPB_circling_earth.jpg

License: CC BY-NC 3.0

This 2D representation shows how Earth's gravity affects other objects near it
[Figure2]

Newton’s law of gravity explains how some of the factors affect Earth’s gravity. Watch this video to review Newton’s law: